Device for controlling list and level of pontoon

ABSTRACT

For a floating dry dock comprising a plurality of pontoons which are interconnected, means for leveling each pontoon. The apparatus has two interconnected systems, one of which corrects the list or inclination of the pontoon and the other of which controls the depth of flotation. Each pontoon has a vertical pipe with a float in it which is responsive to the depth of flotation which operates an indicator for the second system. Automatic controls may be provided for both systems and the systems for each pontoon may be coupled with the systems for the other pontoons in the dry dock.

Unite Yamura 1 June 5, 1973 54 DEVICE FOR CONTROLLING LIST 1,107,7688/1914 Donnelly ..114 45 AND LEVEL OF PONTOON 2,024,822 12 1935 Hort..114 125 [75] Inventor: letoshi Yamura, Nerimaku, Tokyo, PrimaryExaminer Milton Buchler Japan Assistant ExaminerS. D. Basinger [73]Assignee: Mitsui Shipbuilding and Engineering y & Howson Co. Ltd.,Tokyo, Japan [57] ABSTRACT [22] Filed: Nov. 18, 1970 [52] US. Cl..ll4/45, 114/125 [51] Int. Cl ..B63c l/02 [58] Field of Search..114/45, 125

[56] References Cited UNITED STATES PATENTS 1,333,580 3/1920 Ximenez..114/45 2,470,850 5/1949 Harris ..l14/45 2,385,341 9/1945 Bayley ..114/45 For a floating dry dock comprising a plurality of pontoons whichare interconnected, means for leveling each pontoon. The apparatus hastwo interconnected systems, one of which corrects the list orinclination of the pontoon and the other of which controls the depth offlotation. Each pontoon has a vertical pipe with a float in it which isresponsive to the depth of flotation which operates an indicator for thesecond system. Automatic controls may be provided for both systems andthe systems for each pontoon may be coupled with the systems for theother pontoons in the dry dock.

2 Claims, 7 Drawing Figures lli PATENTEDJUH 5 ma w it. Z

FIGS! Ff FIG.30 F|G.3b FIG.3

DEVICE FOR CONTROLLING LIST AND LEVEL OF PONTOON This invention relatesto a device for controlling list and level of pontoons, and moreparticularly to device suited for use in a floating dock comprising aplurality of pontoons which are joined together.

The object of the present invention is to provide a controlling devicewhich may maintain each pontoon in horizontal state and keep the topsurface of the pontoon in flush relationship with those of the otherpontoons.

The device according to the present invention comprises pontoons ofwhich watertight subdivision is divided into the front and rear, leftand right, and central compartments a system for correcting list orinclination of each pontoon by feeding water into the front and rear andleft and right compartments in the respective pontoons and a system inwhich water feed and discharge are conducted in the central compartmentso as to uniformalize the level of each pontoon.

The present invention will be understood from the following descriptiontaken in connection with the accompanying drawings in which:

FIG. 1 is a plan view showing the watertight compartments and pipingprovided in the interior of a pontoon according to the presentinvention;

FIG. 2 is a cross sectional view illustrating a condition in which waterfeeding is conducted in the interior of a floated pontoon;

FIGS. 3 a, 3b and 3c are diagrammatic views illustrating the operationsof a reversible type pump;

FIG. 4 is a side view illustrating a condition in which the structureson two pontoons are joined together and FIG. 5 is a sectional view of adevice for detecting the draught after submergence of the pontoon.

Now, the invention will be described in detail with reference to theaccompanying drawings. As shown in FIG. 1 watertight bulkheads areprovided in the interior of a pontoon to divide the interior into afront compartment 1, a rear compartment 2, a port compartment 5, astarboard compartment 6 and a central compartment 9, into which water isto be fed. In the center of said central compartment is also provided amachinery chamber compartment 12 in which reversible floweffectingmeans, in the present instance pipe and pump means 4, 8 and 11 aredisposed. No water is introduced into the machinery chamber compartment.At the top of each pontoon is provided a watertight manhole which isclosed when the pontoon is submerged. The front and rear compartments 1and 2 are communicated with each other through a pipe 3 with thereversible pump means 4, and the right and left compartments 5 and 6 arecommunicated with each other through a pipe 7 having the reversible pumpmeans 8, while the central compartment 9 is communicated with outsidewater through a pipe 10 with the reversible pump means 11. The left endof the pipe 10 opens out through the bottom of the pontoon and iscommunicated with outside water. The reversible pump means 11 iscommunicated with the compartments 1 or 2 and 5 or 6 through a sluicevalve (not shown), to communicate the compartments with outside water toadjust the amount of water in each compartment.

The portions denoted by reference numbers I to 8 belong to the systemfor controlling each pontoon in horizontal state. While the portionsindicated by reference numbers 9 to 1 I represent compartments and waterfeeding and discharging means which belong to another system by whicheach pontoon is controlled to keep its waterline level at apredetermined height and to be adjusted in flush relation with thelevels of other pontoons.

Referring now to FIG. 2, there are shown a pontoon in cross section anda structure, such as a ship building block, mounted on said pontoon,where reference number 13 denotes such structure and the oblique linesin the pontoon indicate water fed thereinto. It will be noted that, inthis case, part of water in the starboard watertight compartment 6 istransferred into the port watertight compartment 5 to counterbalance theunbalanced load of the structure 13, thereby to keep the horizontaldisposition of the pontoon. Correction of a list of the pontoon in thelongitudinal direction by transfer of water from the front to rearcompartment, or vice sersa, may be conducted in the same manner.

The reversible purn means, as shown diagrammatically in FIG. 3,comprises a pump 14, a pair of threeway valves 15 disposed in front andin back of the pump, and a circular pipe encircling said pump 14 withflow pipe lines extending leftwise and rightwise from middle parts ofsaid circular pipe. By suitable switching of the three-way valves 15, itis possible to let water flow from right to left as shown in FIG. 3a orto left it flow from left to right as shown in FIG. 30, or to let itflow circularly, without allowing rightwise or leftwise transfer, whileoperating the pump as shown in FIG. 3b.

The central reversible pump means may be replaced by an arrangement inwhich the top of the watertight compartment is made air tight and isconnected with a compressed air pipe and water in the watertightcompartment is transferred by opening or closing of an air valve toallow ingress of outside water or egress of inside water. The pontoonlist is detected by such means as pendulum, draught difference, etc.,while the pontoon level is detected by a draught gauge, and thechangeover valve for water feed or discharge is operated correspondinglythereto, thereby to control the list and level of each pontoon.

FIG. 4 shows still another embodiment where the structures 13, 13a on apair of pontoons are joined to gether and then the pontoons aresubmerged, thereby the structures may be floated up and drawn out fromthe pontoons. At the sides of the pontoons are provided buoyancy tanks16 for maintaining floating stability of the pontoons. Numeral 17 in thefigure indicates the draught at the time of completion of the structureassemblage, and numeral 18 indicates the draught where the pontoons aresubmerged and the structure thereon can be drawn out in a floatedcondition. A large amount of water is introduced into the pontoons whichare on the level of draught 17 until they sink down to the draught line18. On each of the floating tanks 16 are given the depth indications(not visible in the drawings) for indicatng the draught to providevisual guidance. In the inside of each floating tank 16 is provided avertical pipe 19 which extends to the bottom of the pontoon, as shown inFIG. 5, and a float 20 adapted to indicate the draught depth is floatedin said vertical pipe. The float 20 is suspended by a cable which ispassed round a pulley 21 provided a top the tank 16 and connected to aweight 22. Rotation of said pulley is relayed to a draught detectingsignal transmitter which, in turn, actuates a draught indicator arrangedon a centralized meter board, whereby water may be introduced into thepontoon to correct list and water line level of each pontoon after ithas been submerged.

This may be conducted under automatic control,

After the structures on the pontoons have been floated up and drawn outfrom the latter, water is dis-. charged out of the pontoons to allowthem to float up while keeping their horizontal disposition and samelevel relation with each other. This water discharge may be conductedunder automatic control. When structures are assembled on three or morepontoons, it is also possible to control water feed and discharge in thesame manner as described above so as to maintain their horizontalalignment.

Thus, according to the present invention, control for pontoon list andlevel by water feed and discharge into or out of the interiorcompartments in each pontoon is separated into two systems whichcomprise a list correcting system and a level correcting system, so thatthe controlling operation is simplified and, if desired, full automationof the operation is also made possible with ease.

What is claimed is:

1. In a device for controlling list and waterline level of pontooncharacterized in that the interior of the pontoon is divded bywatertight bulkheads into front and rear compartments, right and leftcompartments and a central compartment, piping and reversiblefloweffecting means for communicating said front compartment with rearcompartment to correct fore and aft list without substantial change inthe water-line level, second piping and reversible flow-effecting meanscommunicating said right compartment with left compartment to correctport and starboard list without substantial change in the water linelevel, and third piping and reversible flow effecting meanscommunicating said central compartment with outside water to control thewaterline level without substantial change in list, said reversibleflow-effecting means comprising a unidirectional pump, a circular pipeencircling said pump, a pair of three-way valves connecting the intakeand exhaust of said pump with said circular pipe, said two valvesdividing said circular pipe into separated segments, and a flow pipeconnected to each segment so that by manipulation of said valves,operation of said pump effects flow into one flow pipe and out theother, or effects flow out the one and into the other, or effects flowthrough the pump without flow through said flow pipes.

2. A device according to claim 1 including a vertical pipe extendingupwardly from the bottom of the pontoon, a float in said pipe and apulley supporting said float at the water level whereby a change in thewater line level of said pontoon effects rotation of said pulley.

1. In a device for controlling list and waterline level of pontooncharacterized in that the interior of the pontoon is divded bywatertight bulkheads into front and rear compartments, right and leftcompartments and a central compartment, piping and reversibleflow-effecting means for communicating said front compartment with rearcompartment to correct fore and aft list without substantial change inthe water-line level, second piping and reversible flow-effecting meanscommunicating said right compartment with left compartment to correctport and starboard list without substantial change in the water linelevel, and third piping and reversible flow effecting meanscommunicating said central compartment with outside water to control thewaterline level without substantial change in list, said reversibleflow-effecting means comprising a unidirectional pump, a circular pipeencircling said pump, a pair of three-way valves connecting the intakeand exhaust of said pump with said circular pipe, said two valvesdividing said circular pipe into separated segments, and a flow pipeconnected to each segment so that by manipulation of said valves,operation of said pump effects flow into one flow pipe and out theother, or effects flow out the one and into the other, or effects flowthrough the pump without flow through said flow pipes.
 2. A deviceaccording to claim 1 including a vertical pipe extending upwardly fromthe bottom of the pontoon, a float in said pipe and a pulley supportingsaid float at the water level whereby a change in the water line levelof said pontoon effects rotation of said pulley.